T-square.



l. MIHALI'NEC.

T-SQUARE.

APPLICATION msu MAR. 19. 191s.

1,287,072. A y l @muted De@.10,1918.

l To all whom t may concern:

i citizen of the United States, residin vJon MIHALINEC, or MENLo PARK, CALIFORNIA.

MIHA'LINEG, a at Menlo Park, in the countyof San ateo and State of California, have invented new and useful Improvements in T-Squa'res, of which the following is a specification.

'This invention relates to- T-squares such Be it known that I, Jon

as are generally used by draftsmen', the object in view being to produce a satisfactory, reliable and accurate device of the character referred to embodyin in connection with a vmain body` or bla e,`and a head,

Specification of Letters Patent.

t treme point of the gage 7 lies direetlyiin the 'center of the are on which the greater poi'- ,fr-SQUARE.

j Patented Dee. 10,1918.

Application led. Haich 19, 1918. Serial No. 223,324.

tion of' said openin is described. Between the opening 6 and t e adjacent extremity of the blade 1, the latter is formed with a p transversely extending groove or seat\8 in which is secured a strip 9. Extending from the center of said strip 9 through a hole formed by a ferrule O, fastened to the T- novel means' for permitting said members to be adjustedin angular relation to each other and' firmly clamped when the desired angular adjustment has l been obtained.

The invention consists of the features of' construction, combination and arrangement of partsfhereinafter Afully described and claimed, reference being had to the accompanying drawing, in which z j Figure 1 is a plan view ofthe improved T-square.

Fig-.2 lis anenlarged vertical section on the line 2--2 ofFig. 1, looking in the direction of the arrows.

Fig. 3 i's a horizontal section on the line "3 3 of Fig. 2. 4

Fig. 4 is a transverse verticalv section on line 4-4 of Fig. 2.

Fig. 5 is a similarview on line 5'.5 of Fig. 1.` v

The improved T-square comprises the main body or blade 1 -and 'the T-head 2. The parts 1 and 2 may be constructed of any desiredY or` preferred dimensions according .to the particular. use to which the device is.

' a depressed part 2O which is designed for to be applied. j

Thel blade 1 is formed at the opposite edges thereof with ribs 3 and graduated strips 4 are secured to the opposite lateral edges of theblade 1, said strips being formed with grooves 5 in the inner edges thereof'to receive and tightly lit the ribs 3. In the preferred embodiment of the invention, one of the graduated strips contains the English measurements while the other head proper is a pivot stud 11 havin at the opposite end thereof 'a disk-shaped secured to the stud or pivot 11 by a screw 13 or the equivalent thereof. The object of the construction just described will hereinafter appear. j n

Secured to the inner edge of the head 2 is ead v12 v a facing strip 14 adapted to rest against the edge ofthe drawing board .in connection Y with which'the T-square is used. Extending along the opposite outer edge of'the head 2 'and around the ends thereof is a binding strip 15 of metal, the same in width as the y thickness of the body of the head 2.

"opposite outer corners of the'head are'beveled as shown at 16 and thestrip 15 extends around and protects such beveled corners. The strip 15 also extends across the opposite ends of the head 2 and the extremities of said strip are bent inwardly to form retaining fingers 17 which are inlaid in the lbody of the head.l Arranged centrally of the strip 15 and extending inwardly therefrom is a comparatively thin and generally arcuate gage strip 18 which is graduated in degrees as indicated at 19 in order to enable a deiithe blade 1 and the head 2. One end porstrips contain measurements in the metric` system.

tion of the strip 15 is inwardly offset to form the reception of the milled head 21 of a clamping screw 22; the head 21 being seated flush in the depressed part 20 of the binding strip 15. The inner end portion of the clamping screw 22 is threaded as shown at 23 -and is inserted through a stationary nut 24 having inwardly projecting parallel guides or Iflanges 25. Mounted forsliding movement between the guides 25 is a head 26 of a clamp 27 having a concaved clamping edge. 28 designed to bear against the pivot stud 11 so as to prevent any relative movement between the blade 1 and the head 2. By loosening the screw 22, the clamping action between the member 21 and the pivot or stud 11 is relieved, enabling the head 2 to be adjusted into a new angular relation to the blade 1. The are of the gage strip-18 such that the outer edge of said strip registers with the extreme tip of the gage point 7 as shown in Fig. 1.

Having thus fully described my inven-` tion, I claim l. In a T-square, the combination of a blade, a head having a pivotal relation to said blade, a pivot stud carried by oneof said members, a clamping screw extendingl lengthwise of said head and operable at one extremity of the head, a stationary nut through which the inner end portion vof said screw is threaded, guiding `means forming ypart ofand projecting from said nut, and a clamping member'for cooperation with said stud, said clamping-member being slidably related to said guiding means and adapted for actuation by said clamping screw.

, 2. In a T-square, the combination of a blade, a head having a pivotal rela-tion to said blade, a rpivot stud carried byV one of said members, a clamping screw extending lengthwise of said head and operable at one end of ,the head, a stationary nut through Awhich the inner end portion of said screw isthreaded, guiding means projecting from said nut a clam in member for eo era -tion With said stud, said clamping member being slidably related to said guiding means and adapted for actuation by said clamping screiv-said blade being formed lWith an obi servation opening extendingtherethrough, a gage point extending to the center of said opening, a binding strip secured to the marginal edge of the head, and an arcuate gage strip extending inwardly from and having a positive connection with said binding strip,I

eration With said stud, said clamping member being slidably related to said guiding means and adapted for actuation by said clamping screw, said blade being formed with an observation opening extending therethrough, a gage point extending to the center of said opening, a binding strip secured to the marginal edge of the head and having an offset portion received in a depression in one end of the headand adapted to receive the head of the clamping screiv, and an arcuate gage strip extending inwardly Jfrom and having a positive connection ivith said binding strip, said arcuate gage strip being inlaid in the head of the iT-square and being graduated to register ivith said gage point.

In testimony whereof I atlix my signature.

JOE MIHALINEC. 

